As of June 6, 2003 the new standard for Metropolitan Statical Areas was put into effect. The new standards known as Core Based Statical Areas (CBSAs), both replace and supersede the previous standards used to define MSAs.

The definitional standards for CBSAs were developed based on analysis of population and commutation data collected in the 2000 Decennial Census. All CBSAs have at least one Central County containing an Incorporated Place or Census Designated Place (CDP) with a population of 10,000 or more. CBSAs are divided into two categories- Metropolitan Statistical Area and, now, Micropolitan Statistical Areas.

Typically the new MSAs follow the “old “ MSA geographies, however, in some cases there is a significant difference in the geographic composition of the new MSAs. The category Micropolitan Statistical Areas are new and contain counties that were previously non-metropolitan.

Metropolitan Statistical Area- A Core Based Statical Areas (CBSA) associated with at least one urbanized area with a population of 50,000 or more, based on the 2000 Census. A Metropolitan Statistical Area is comprised of the Central County or counties containing the core urban area, plus any abject/outlying counties that have a high degree of social and economic integration with the Central County. As of June 6,2003 a total of 362 Metropolitan Statistical Areas that incorporate 1,090 counties, containing approximately 83% of the US population were reported.

Micropolitan Statistical Area- A Core Based Statical Areas (CBSA)with at least one urban cluster containing between 10,000 and 50,000 people, based on the 2000 census. A Micropolitan Statistical Area is comprised of the Central County or counties containing the core urban area, plus any abject/outlying counties with a high degree of social and economic integration. There are now (as of 6/2003) 560 Micropolitan Statistical Areas (all new) comprised of 674 counties containing 10% of the US pop.

Some of the larger Metropolitan Statistical areas are subdivided into Metropolitan Divisions that mirror “old” MSA geography. These Metropolitan Statistical Areas are similar in geographic composition to the “old” Consolidated Metropolitan Statistical Areas (CMSAs). For example, the Dallas-Fort Worth-Arlington MSA is comprised of the Dallas-Plano-Irving and Fort-Worth-Arlington Metropolitan Divisions. The county definitions for these divisions are identical to the “old” Dallas and Fort Worth MSAs.

If you would like to learn more about CBSAs link up to the following websites:
http://www.whitehouse.gov/omb/bulletins/b03-04.html
http://www.census.gov/population/www/estimates/metroarea.html
http://genesys-sampling.com